Tashkent university of information technology named after muhammad al-khwarizmi

Data Security Threat: Unauthorised users can access important data of an organization if centralized data repository is not secured properly by the LAN administrator.

LAN Maintenance Job: Local Area Network requires a LAN Administrator because, there are problems of software installations or hardware failures or cable disturbances in Local Area Network. A LAN Administrator is needed at this full time job.

Covers Limited Area: Local Area Network covers a small area like one office, one building or a group of nearby buildings.

Metropolitan Area Network (MAN)

It was developed in 1980s.It is basically a bigger version of LAN. It is also called MAN and uses the similar technology as LAN. It is designed to extend over the entire city. It can be means to connecting a number of LANs into a larger network or it can be a single cable. It is mainly hold and operated by single private company or a public company.

Characteristics of MAN

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  It generally covers towns and cities (50 km)
  
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  Communication medium used for MAN are optical fibers, cables etc.
  
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  Data rates adequate for distributed computing applications.
  

Advantages of MAN

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  Extremely efficient and provide fast communication via high-speed carriers, such as fibre optic cables.
  
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  It provides a good back bone for large network and provides greater access to WANs.
  
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  The dual bus used in MAN helps the transmission of data in both directions simultaneously.
  
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  A MAN usually encompasses several blocks of a city or an entire city.
  

Disadvantages of MAN

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  More cable required for a MAN connection from one place to another.
  
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  It is difficult to make the system secure from hackers and industrial espionage(spying) graphical regions.